32°, 6.53°, and 10.84°) corresponding to d values of 4.07, 2.04, 1.35, and 0.82 nm, respectively. The corresponding d values follow a ratio

of 1:1/2:1/3:1/5, suggesting a lamellar-like structure of the aggregates in the gel [43]. As for the curves of CH-C1 in other solvents, isooctanol, n-hexane, nitrobenzene, and aniline, the minimum 2θ values are 2.62°, 3.02°, 3.08°, and 4.36°, corresponding to d values of 3.37, 2.93, 2.87, and 2.03 nm, respectively. The change of values can be mainly attributed to the different assembly modes of the gelator in various solvents. Furthermore, the curves of CH-C1, CH-C3, and CH-C4 in nitrobenzene were also compared to investigate the spacer Selleck SCH727965 effects on assembly modes. Minimum 2θ peaks were observed at 4.14° and 2.74°

for CH-C3 and CH-C4, respectively. The corresponding d values are 2.14 and 3.23 nm, respectively. The XRD results demonstrated Pictilisib solubility dmso again that the spacers had great effects on the assembly modes of these imide gelators. Figure 5 X-ray diffraction patterns of xerogels. (a) CH-C1 (a, isooctanol; b, n-hexane; c, 1,4-dioxane; d, nitrobenzene; and e, aniline); (b) a, CH-C1; b, CH-C3; and c, CH-C4, in nitrobenzene. It is well known that hydrogen bonding plays an important role in the self-assembly process of organogels [44, 45]. At present, we have measured the FT-IR spectra of xerogels of all compounds in order to further and investigate the assembly process. Firstly, the xerogels of CH-C1 were taken as examples, as shown in Figure  6a. As far as the spectrum of CH-C1 xerogel in nitrobenzene, some main peaks were observed at 3,436, 3,415, 1,728, and 1,593 cm-1. These bands can be attributed to the N-H stretching, C=O stretching of ester, amide I band, and benzene ring, respectively [34, 46, 47]. These bands indicate H-bond formation between intermolecular amide and carbonyl groups in the gel state. The

spectra of other xerogels in different buy MLN8237 solvents are Thymidylate synthase different, suggesting the different H-bond and assembly modes of the gelator in various solvents. In addition, it is interesting to note that the spectra of xerogels of CH-C1, CH-C3, and CH-C4 in nitrobenzene were compared in Figure  6b, showing an obvious change. The main peaks attributed to the C=O stretching of ester and the amide I band shifted to 1,726 and 1,707 as well as 1,735 and 1,716 cm-1 for CH-C3 and CH-C4, respectively. This implied that there were differences in the strength and direction of the intermolecular hydrogen-bond interactions in these xerogels. The present data further verified that the spacer in molecular skeletons can regulate the stacking of the gelator molecules to self-assemble into ordered structures by distinct intermolecular hydrogen bonding. Figure 6 FT- IR spectra of xerogels. (a) CH-C1 (a, isooctanol; b, n-hexane; c, 1,4-dioxane; d, nitrobenzene; e, aniline; and f, chloroform solution); (b) a, CH-C1; b, CH-C3; and c, CH-C4, in nitrobenzene.